#include <stdio.h>
#include <stdlib.h>
#include "sm4.h"
 static void zeroize( void *v, unsigned int n ) 
{ 
volatile unsigned char *p = (unsigned char *)v; while( n-- ) *p++ = 0;
}
#ifndef GET_UINT32_BE 
#define GET_UINT32_BE(n,b,i)
{
(n) = ( (unsigned int) (b)[(i) ] << 24 )
    | ( (unsigned int) (b)[(i) + 1] << 16 )
    | ( (unsigned int) (b)[(i) + 2] << 8 )
    | ( (unsigned int) (b)[(i) + 3] );
} 
#endif

#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i)
{
(b)[(i) ] = (unsigned char) ( (n) >> 24 );
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 );
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 );
(b)[(i) + 3] = (unsigned char) ( (n) );
}
#endif 
#define SHL(x,n) (((x) & 0xFFFFFFFF) << n) 
#define ROTL(x,n) (SHL((x),n) | ((x) >> (32 - n)))

#define SWAP(a,b) {unsigned int t = a;a=b;b=t;t=0;}
 static const unsigned char SboxTable[16][16] = 
{
{0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05}, {0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99}, {0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62}, {0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6}, {0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8}, {0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35}, {0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87}, {0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e}, {0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1}, {0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3}, {0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f}, {0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51}, {0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8}, {0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0}, {0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84}, {0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48} 
};

 static const unsigned int FK[4] =  {0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc};

 static const unsigned int CK[32] = 
{
 0x00070e15,0x1c232a31,0x383f464d,0x545b6269, 0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9, 0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249, 0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9, 0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229, 0x30373e45,0x4c535a61,0x686f767d,0x848b9299, 0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209, 0x10171e25,0x2c333a41,0x484f565d,0x646b7279 
};

 static unsigned char sm4Sbox(unsigned char inch)
 {
 unsigned char *pTable = (unsigned char *)SboxTable;
 unsigned char retVal = (unsigned char)(pTable[inch]);
 return retVal;
 }

static unsigned int sm4Lt(unsigned int ka)
 {
 unsigned int bb = 0;
 unsigned int c = 0;
 unsigned char a[4];
 unsigned char b[4];
 PUT_UINT32_BE(ka,a,0) 
b[0] = sm4Sbox(a[0]); 
b[1] = sm4Sbox(a[1]);
 b[2] = sm4Sbox(a[2]);
 b[3] = sm4Sbox(a[3]);
 GET_UINT32_BE(bb,b,0)
 c =bb^(ROTL(bb, 2))(ROTL(bb, 10))(ROTL(bb, 18))^(ROTL(bb, 24));
 return c; 
}

 static unsigned int sm4F(unsigned int x0, unsigned int x1, unsigned int x2, unsigned int x3, unsigned int rk)
{
 return (x0^sm4Lt(x1^x2^x3^rk)); 
}

 static unsigned int sm4CalciRK(unsigned int ka)
 {
 unsigned int bb = 0; 
 unsigned int rk = 0;
 unsigned char a[4];
 unsigned char b[4];
 PUT_UINT32_BE(ka,a,0)
 b[0] = sm4Sbox(a[0]);
 b[1] = sm4Sbox(a[1]); 
 b[2] = sm4Sbox(a[2]);
 b[3] = sm4Sbox(a[3]); 
 GET_UINT32_BE(bb,b,0) 
 rk = bb^(ROTL(bb, 13))^(ROTL(bb, 23));
 return rk; 
}

static void sm4_setkey( unsigned int SK[32], unsigned char key[16] )
 {
 unsigned int MK[4];
 unsigned int k[36];
 unsigned int i = 0;

GET_UINT32_BE( MK[0], key, 0 );
GET_UINT32_BE( MK[1], key, 4 );
GET_UINT32_BE( MK[2], key, 8 );
GET_UINT32_BE( MK[3], key, 12 );
k[0] = MK[0]^FK[0];
k[1] = MK[1]^FK[1];
k[2] = MK[2]^FK[2];
k[3] = MK[3]^FK[3];
for(; i<32; i++)
  {
    k[i+4] = k[i] ^ (sm4CalciRK(k[i+1]^k[i+2]^k[i+3]^CK[i]));
    SK[i] = k[i+4];
  }

}

 static void sm4_one_round( unsigned int sk[32], 
unsigned char input[16],
 unsigned char output[16] )
 {
 unsigned int i = 0; 
unsigned int ulbuf[36];

memset(ulbuf, 0, sizeof(ulbuf));
GET_UINT32_BE( ulbuf[0], input, 0 )
GET_UINT32_BE( ulbuf[1], input, 4 )
GET_UINT32_BE( ulbuf[2], input, 8 )
GET_UINT32_BE( ulbuf[3], input, 12 )

while(i<32)
   {
    ulbuf[i+4] = sm4F(ulbuf[i], ulbuf[i+1], ulbuf[i+2], ulbuf[i+3], sk[i]);
    i++;
   }

PUT_UINT32_BE(ulbuf[35],output,0);
PUT_UINT32_BE(ulbuf[34],output,4);
PUT_UINT32_BE(ulbuf[33],output,8);
PUT_UINT32_BE(ulbuf[32],output,12);

 }

void sm4_init( sm4_context *ctx ) 
{
 memset( ctx, 0, sizeof( sm4_context ) ); 
}

void sm4_free( sm4_context *ctx ) 
{
 if( ctx == NULL )
 return;

zeroize( ctx, sizeof( sm4_context ) );

}

 void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] )
 {
 ctx->mode = SM4_ENCRYPT;
 sm4_setkey( ctx->sk, key );
 }

 void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] )
 {
 int i;
 ctx->mode = SM4_DECRYPT;
 sm4_setkey( ctx->sk, key );
 for( i = 0; i < 16; i ++ )
    {
        SWAP( ctx->sk[ i ], ctx->sk[ 31-i] );
    }
 }


int sm4_crypt_ecb( sm4_context *ctx,
      int mode,
      int length,
      unsigned char *input, 
      unsigned char *output)
 { 
while( length > 0 ) 
{
 sm4_one_round( ctx->sk, input, output );
 input += 16; 
 output += 16;
 length -= 16; 
}

return( 0 );

}

 int sm4_crypt_cbc( sm4_context *ctx,
 int mode, 
 int length,
 unsigned char iv[16],
 unsigned char *input,
 unsigned char *output )
 {
 int i;
 unsigned char temp[16];
 unsigned char *pbIV = NULL;

    pbIV = (unsigned char *)malloc(16);
    memcpy(pbIV, iv, 16);

    if( mode == SM4_ENCRYPT )
 {
 while( length > 0 )
 {
 for( i = 0; i < 16; i++ ) 
 output[i] = (unsigned char)( input[i] ^ pbIV[i] );

         sm4_one_round( ctx->sk, output, output );
         memcpy( pbIV, output, 16 );

         input  += 16;
         output += 16;
         length -= 16;
     }

    } 
 else 
    {
 while( length > 0 )
    {
 memcpy( temp, input, 16 ); 
 sm4_one_round( ctx->sk, input, output );

         for( i = 0; i < 16; i++ )
             output[i] = (unsigned char)( output[i] ^ pbIV[i] );

         memcpy( pbIV, temp, 16 );

         input  += 16;
         output += 16;
         length -= 16;
       }

     }

    free(pbIV); 
    pbIV = NULL;
    return( 0 );
}


